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Flashcards in shaping earth's crust Deck (30):
1

Weathering

Breakdown and decay of rocks that are exposed to weather

2

Two main types of weathering

Mechanical

Chemical

3

Mechanical weathering example

Freeze thaw action/frost action

1. Water runs into joint/crack in rock

2. Water freezes, expands, putting pressure on rock

3. After freezing + thawing, rock fragments break off

4

Chemical weathering example - rainwater on limestone

1. Rainwater travels through atmosphere

2. Mixes with carbon dioxide

3. Makes weak carbonic acid

4. Falls on limestone

5. Changes calcium carbonate (in limestone) to calcium bi carbonate

6. Process/reaction is carbonation

7. Makes it easier for rainwater to dissolve limestone

5

The burren

Carbonation causes rock to dissolve.

Little material is left ons surface to form soil, appears as bare rock

Landscape looks v barren, known as limestone pavement

Surface covered in lots of cracks. Water has laid in these cracks for long.

6

Grykes

The cracks in the rocks

7

Clints

The slabs of rocks

8

Swallow hole

Sometimes grykes may get bigger and a swallow hole will be formed.

Lets water flow underground,

9

Cave

As water flows beneath surface, it dissolves limestone and cuts out tunnels called caves

10

Cavern

If cave is enlarged, its called a cavern

11

Stalactite

Water containing calcium carbonate drips from ceiling.

Evaporation takes place leaving deposits of calcite

Deposits build up over time to form stalactites

12

Stalagmite

Water containing calcium carbonate drips from ceiling to floor

Evaporation takes place leaving deposits of calcite on floor

Deposits build up over time to form stalagmites

13

Pillar/column

Formed when stalactite and stalagmite join together

(or when stalactite reaches ground or stalagmite reaches ceiling)

14

Flora

Burn has varied plant life and many rare plants can be found such as orchids, ferns, avens

15

Fauna

Burren's wildlife includes green moth, butterlies, wild goats

16

Landscape

Burren ha wide range of scenery for tourists. Attraction include Aliwee caves and Cliffs of Moher

17

History

Burren's monuments and archaeological sites provide evidence of historical settlements. These include dolmens and ring forts

18

Mass movement

Movement of any loose material down slope under influence of gravith.

Loose material incl. loose rock, mud, soil (regolith)

19

Influences of mass movement

Gradient

Water content

Human acitivity

Vegetation

20

Gradient

Fastest when slope is steep

21

Water content

Water acts as lubricant, making regolith heavier + surface slippery

22

Human acitivty

Cutting into hillside during construction of roads + railways creat steeper slope

23

Vegetation

Roots of trees + plants bind soil together, slowing down rate of mass movement

24

Types of mass movement

Classified by speed

slow:
Soil creep

fast:
landslide
bog burst
avalanche

25

soil creep

occur on very gentle slopes

might not be noticed except for effect on surface objects eg. leaning poles, fences, walls

greatest near surface, decreases with depth

26

landslides

Sudden rapid movement of regolith down slope

most common in mountainous areas

may occur along coastal cliffs which have been undermined by sea erosion

27

causes of landslides

road/railway cutting into steep slope

constant erosion by waves causing undercutting of cliffs

earthquakes and their aftershocks can trigger landslides

28

Bog burst

movement of peat down hillside

caused by heavy rain saturating peat

can be caused by human activity such as excavation

29

mudflows

can occur on both gentle + steep slopes

torrential rainfall saturated soil and turns into mud

can occur after volcanic eruption

lahar is a volcanic landslide, mud mixes with lava + ash

30

Denudation

Wearing down of solid + loose materials of Earth's crust

Occurs by weathering + erosion